Ceiling fan

ABSTRACT

A ceiling fan design incorporates a plurality of air-moving blades having a generally vertical orientation. Curvature of the blades causes air to be moved in a generally downward direction. Large blade surface areas are provided to generate desired volumes of air movement at slow speeds.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to electric appliances, and more specifically to a ceiling fan suitable for use in residential or commercial installations.

2. Description of the Prior Art

Ceiling fan designs are similar to those developed in the early 1900s. A typical ceiling fan has an electric motor suspended from a rigid downrod, allowing it to be spaced from the ceiling. A plurality of fan blades, in typically three to six blades, extend horizontally from the fan motor housing and are attached to a rotor.

In order to obtain different design looks, and achieve differentiation in the marketplace, numerous variations on the basic design have been developed. Details of the fan body layout, and fan body and blade designs, have been changed. However, the basic layout of a generally circular fan body with a plurality of horizontally extending blades has not changed.

Variations have been developed in techniques for hanging ceiling fans in order to achieve a different aesthetic appeal. For example, see PCT Publication No. WO 03/040,572. Again, all of these designs include a generally horizontal blade.

While horizontal, angled blades are efficient in moving air in a downward direction, it is typical for such blades to provide a column of relatively moderate air movement directly beneath the fan, with faster air being generated by the blade tips. Peripheral regions of the room receive relatively less air movement. In order to prevent the column of air descending from the rotating fan from moving papers or annoying people in the room, the fan is generally operated at a low speed. This further diminishes air movement throughout the room.

In many installations, it is difficult to obtain adequate movement of air within a room without generating higher than desired airflow speeds. Because the blades are primarily horizontal, they present a relatively small surface area in their direction of movement. Thus, the amount of air actually pushed into movement by the blade is small relative to the air volume desired to be moved in the room.

It would be desirable to provide a fan that provided relatively large amounts of air movement beneath the ceiling fan, but did not require air to be moved at relatively fast speeds.

SUMMARY OF THE INVENTION

In accordance with the present invention, a ceiling fan design incorporates a plurality of air-moving blades having a generally vertical orientation. Curvature of the blades causes air to be moved in a generally downward direction. Large blade surface areas are provided to generate desired volumes of air movement at slow speeds.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is an overall view of a preferred embodiment of a ceiling fan in accordance with the present invention;

FIG. 2 illustrates a preferred technique for hanging a ceiling fan that does not provide a central downrod;

FIG. 3 illustrates a preferred technique for blade attachment; and

FIG. 4 is a schematic view of a preferred latch to be used in connection with the blade attachment technique of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

It will be understood by those skilled in the art that variations on the details described herein are contemplated within the scope of the invention. In particular, any known alternative technique for hanging the fan may be used in place of the one described herein. In addition, the precise curvature and orientation of the blades may be varied as described herein.

FIG. 1 illustrates a ceiling fan 10 in accordance with the present invention. A canopy 12 is attached to the ceiling or other mounting point for the fan, and covers typical mounting and electrical connection hardware (not shown) as is known in the art. The fan itself is suspended from a support ring 14, which is connected to the canopy 12 by a flexible cable 16. A power cable 17 extends through canopy 12 to provide power to the fan motor. Further details of this mounting technique are described in connection with FIG. 2. In addition, the mounting technique is similar, but not identical, to the description contained in pending PCT Application No. WO 03/040,572.

The fan body 18 is suspended from the support ring 14, and includes a rotor portion 20 that rotates below a non-moving, stator portion 22 when the fan is energized. In FIG. 1, the rotor portion 20 of the fan body is approximately an inverted tear-drop shape, but nearly any fan body shape can be used in accordance with the present invention. Because of the orientation of the blades, a fan body 18 that is relatively elongate in a vertical direction will be useful.

Four blades 24 are shown attached to the fan rotor portion 20, although any number of blades may be used as known in the art. As seen in FIG. 1, the blades are oriented in a relatively vertical direction. This orientation may be described in several ways. As shown, the blades 24 are generally longer in a vertical direction than they are in a horizontal direction. Also, the connection region 26 between the blades 24 and the fan body rotor 20 are generally closer to vertical that 45 degrees above a horizontal angle. Although curvature of the fan blades 24 causes certain individual portions of the blades to be relatively horizontal, such as shown at region 28, the overall orientation of the blade is generally vertical.

As can be seen in FIG. 1, the fan blades 24 are curved so as to push some air in a generally vertical, downward direction when the fan motor is energized. However, because only a portion of each fan blade is generally horizontal, additional air will be pushed relatively horizontally, and downwardly at an angle that will cause the air to approach the room floor outside of a column directly beneath the fan. This provides gentle air movement throughout a relatively large room without requiring fast movement of air underneath the fan. In other words, the large vertical surface area of the blades 24 moves a larger volume of air, more slowly.

Referring to FIG. 2, a preferred mounting technique for the fan of FIG. 1 is illustrated. A cable 16 is provided having an attachment loop 30 at both ends. One loop 30 is securely attached to a cable block 32 mounted on the upper side of the canopy 12, while the other cable end 30 is alternately threaded between openings 34 provided in the canopy, and attachment/support arms 36 connected to the support ring 14 on the fan body. This alternating feed of the cable 16 causes the suspended fan to be hung as illustrated in FIG. 1. Once the cable 16 has been fully threaded, the second end 30 is securely attached to the cable block 32.

This hanging technique is similar to that shown in pending PCT Application WO 03/040,572. Suspending the fan using this technique provides a significantly different aesthetic look than the use of a rigid downrod. In addition, the angles of the cable segments prevents the fan from twisting inappropriately, although small amounts of fan twisting about a vertical axis do occasionally occur. The illustrated technique is an alternative to that shown in the pending PCT application, but achieves essentially the same results.

FIG. 3 illustrates a preferred technique for attaching a blade 24 to the rotating portion 20 of the fan body. The rotor portion outer surface preferably is solid, except for a single, angled groove 40 for each fan blade. As seen, the groove 40, and thus a root edge 42 of the blade, is generally oriented in a vertical direction.

The root edge 42 of the blade preferably has slots therein, defining a plurality of teeth such as shown in FIG. 3. A locking tab 44 or other locking technique is preferably provided on the root. In the embodiment shown, a locking tab 44 is shown at the upper end of the root edge 42 of each blade 24.

Inside the slot 40 of the fan rotating portion are a plurality of pins corresponding to the slots in the fan blade. The fan blade 24 is placed into the groove 40, and the slots engage the pins, to support the blade. The blade 24 is inserted an inch or two into slot 40, solidly supporting blade 24 in a fixed position.

Referring to FIG. 4, a spring loaded cam mechanism is pivotally mounted within the fan rotating portion. When the fan blade tab 44 engages the cam, it rotates out of the way until the fan blade has been fully seated. The spring loaded cam them rotates back to its original position, and engages the tab 44 on the blade 24. This prevents the blade 24 from being removed from the fan rotating portion 20 until the cam is physically moved, using a screwdriver or other elongated item, in order to intentionally release the blade.

The described cam locking mechanism can be replaced with any other technique for holding the blade in place. Numerous types of gripping fixtures, slots, and pins can be used as will be appreciated by those skilled in the art. Various arrangements of bolts or screws can also be used. It is only necessary that the blade be held firmly enough in place that it not come loose, or even fall off, during use.

The blade curvature illustrated in the Figures is not the only blade curvature that can be used. The blades can be curved so as to be more vertical or less vertical depending upon how much horizontal versus vertical air flow is desired. Also, orientation of the blades will depend upon the preferred operating speeds for the fan. Blades that are primarily vertical tend to slow down the operating speed of the fan, due to increased air resistance, for any given fan motor design and size.

Preferably, the lower regions of the blades, which are also the trailing edges, are the portions of the blades most horizontally oriented. This leaves the upper portions of each blade relatively vertically oriented. This provides a good mix of horizontally and vertically displaced air during fan operation. This design also allows the blades to engage a large volume of air in a manner similar to a ship's screw, causing more air to be moved for each rotation of the fan than occurs with a traditional design.

While the illustrated blades are smoothly curved, this is not necessary. A smooth curve provides a comfortable pattern of air movement from the fan. However, the blades may be straight if desired, or angled with one or more relatively linear seams in the blade.

The use of blades curved as shown in FIG. 1 had proven especially useful in practice. Smooth curves, with more horizontal regions at the bottom of the blade, generates a relatively large amount of overall air movement at a low speed. In addition, the fan operation is extremely quiet, because it is operated at slow speeds. Because more air is moved for a given fan rotational speed, the described design is generally quieter than a traditional design for a given volume of air movement.

As opposed to traditional ceiling fans, which have blades that are only slightly angled from a horizontal orientation, the present design provides for blades that are much more steeply vertically angled. In the prior art, ceiling fan blades are oriented at angles approximately less than 45 degrees from a horizontal plane; in many instances these blades are angled at 20 degrees or less from the horizontal. In contrast, the present blades have at least a portion thereof oriented at an angle greater than 45 degrees from the horizontal. Although some portions of the illustrated blades are relatively horizontal, other portions are practically vertical in orientation.

The illustrated blades have a vertically oriented surface area that is greater than the more horizontally oriented surface area. However, the relative area is dedicated to blade portions oriented more than and less than 45 degrees from horizontal may be varied as desired. Blades that are more horizontally oriented provide a greater percentage of air movement directly beneath or near to the fan. The greater the percentage of blade area dedicated to a vertical orientation, the more air movement will be realized in more distanced portions of the room.

It will be appreciated by those skilled in the art that vertically modified blade orientations, such as described above, provide a ceiling fan having significantly different operational characteristics than a traditional ceiling fan. In addition to different operating characteristics, the fan provides a different aesthetic look. Although the illustrated fan shows a relatively contemporary look for the fan body itself, vertically oriented blades as described herein can be used with more traditional fan body designs. Blades having a portion thereof oriented more vertically than 45 degrees from a horizontal plane need not be as relatively tall as those shown in the illustrations, but they may look more like traditional fan blades. For example, a traditional fan blade having a “twist” so that the outer edge thereof is more vertically oriented than the inner end can also be used to provide some of the benefits set forth above. Because of the additional air moved by a more vertically oriented blade, fan motors will generally have to be selected to be more powerful than would otherwise be the case for a more traditionally oriented fan blade.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. 

1. A ceiling fan, comprising: a fan stator portion adapted for connection to a ceiling; a fan rotor portion rotatably connected the stator portion, and adapted to rotate about a substantially vertical axis; and a plurality of blades connected to and carried by the rotor portion, wherein the blades each have a vertical dimension greater than a horizontal dimension.
 2. The ceiling fan of claim 1, wherein each blade is curved so as to have an upper region thereof that is oriented more vertically than a lower region thereof.
 3. The fan of claim 1, wherein an inner edge of each blade connects the blade to the rotor portion, and wherein the inner edge is at an angle more than 45 degrees above horizontal.
 4. The fan of claim 3, wherein an outer region of each blade is more horizontally oriented than the inner edge.
 5. A ceiling fan, comprising: a fan stator portion adapted for connection to a ceiling; a fan rotor portion rotatably connected the stator portion, and adapted to rotate about a substantially vertical axis; and a plurality of blades connected to and carried by the rotor portion, wherein the blades each have a majority of their surface oriented closer to a vertical axis direction than to a horizontal direction.
 6. The ceiling fan of claim 5, wherein an angle between a leading edge of each blade and a trailing edge of each blade is greater than 45 degrees above a horizontal plane.
 7. The ceiling fan of claim 5, wherein each blade has a vertical dimension greater than a horizontal dimension.
 8. The ceiling fan of claim 5, wherein each blade is curved to provide a constantly varying angle to the vertical across the entire surface of the blade.
 9. The ceiling fan of claim 5, wherein a lower edge of each blade is more horizontally oriented than an upper edge. 